Heat protections for workers: a regulatory update

Three years ago, Safety+Health offered an overview of efforts by the federal government and states to address heat injury and illness prevention on the job.

At the time, five states – California, Colorado, Minnesota, Oregon and Washington – had some form of a heat-related standard in effect. Colorado’s standard covers agricultural workers, while Minnesota’s applies only to indoor workplaces.

Since 2023, Maryland and Nevada have finalized heat regulations for indoor and outdoor workers. Meanwhile, many other potential rules are in various stages of the legislative or regulatory process.

Here’s a rundown of important developments over the past few years.

Federal OSHA

On April 10, OSHA issued a revision of its National Emphasis Program on outdoor and indoor heat-related hazards.

The updated NEP, set to expire in 2031, features a revised list of 55 “high-risk industries,” along with information on how agency investigators will evaluate heat illness and injury prevention programs.

The NEP notes that OSHA’s heat-related inspections have accounted for 6% of all federal-level agency inspections in the past five years. That’s up from 0.5% in the five-year period that preceded the 2022 NEP.

In August 2024, the agency published a proposed rule on heat illness and injury prevention in outdoor and indoor settings. Last summer, OSHA conducted a series of informal hearings with stakeholders, but next steps on a heat standard were unknown as of press time.

Maryland

Maryland’s heat standard covering both indoor and outdoor workers went into effect in September 2024.

As OSHA’s proposed rule would mandate, the state’s rule requires covered employers to develop and implement a heat illness prevention plan. The Maryland regulation also includes provisions for acclimatization, drinking water, shade, training and emergency response. Those requirements go into effect when the heat index reaches 80° F.

Further, the regulation sets special “high-heat” requirements for when the heat index reaches 90° F. They include two-way communication with employees and scheduling work and rest periods.

Nevada

Nevada became the seventh state to craft a heat regulation, which went into effect in April 2025. It also covers outdoor and indoor workers.

The state requires employers with 10 or more employees to conduct a one-time, written Job Hazard Analysis if workers are exposed to heat for more than 30 minutes in any one-hour period (excluding breaks). The JHA must be completed “before a task for a job is undertaken for the first time” or when a job task “materially changes.”

To determine if a job task has materially changed, a guidance document from the Nevada Division of Industrial Relations advises employers to “consider any change … that could increase an employee’s exposure to heat, including, but not limited to, changes in the work environment, work processes or exertion levels.”

A written heat safety plan must include provisions for:

• Monitoring workplace conditions
• Worker access to potable water
• Rest breaks for workers exhibiting signs or symptoms of a heat illness
• Methods of cooling for employees
• Training
• Emergency response

The requirements, however, have drawn criticism. The Laborers’ Health and Safety Fund of North America, for instance, has called the regulation “weak” because it’s less prescriptive than other heat standards. In a December 2024 press release, LHSFNA asserted the standard lacks:

• Temperature thresholds. “The standard (leaves) it up to the employer to decide which tasks could cause heat illness and when to implement protections.” The release notes that Maryland’s standard, for comparison’s sake, has high-heat procedures when the heat index reaches 90° F.
• Provisions for acclimatization. LHSFNA pointed out that more than 70% of heat-related deaths occur in an employee’s first week on the job, before they’ve been acclimated to high temperatures. “By not making employers even consider acclimatization in their written plan, new workers will remain at higher risk.”
• Strong language on water and shade. “Nevada’s standard doesn’t specify how much water employers need to provide per employee or how close shade structures must be to the working area.”
• Worker access to rest breaks. “The standard only requires workers to be given rest breaks after they’re already showing the signs or symptoms of heat illness. This leaves management to assess those symptoms or forces individual workers to speak up. Stronger standards mandate rest breaks during high-heat conditions (e.g., at least 10 minutes every two hours when 90° F or more).”

The Nevada rule is widely considered a “performance-based” standard.

Many industry and employer stakeholders want the same kind of regulation from federal OSHA, if the agency chooses to finalize a heat rule.

Virginia

Virginia will likely become one of the next states with a heat regulation.

On April 13, Gov. Abigail Spanberger (D) signed companion bills H.B. 1092 and S.B. 288 (both of which have identical text). The new law requires the commonwealth’s Safety and Health Codes Board to develop a heat regulation no later than May 1, 2028.

That regulation, for both indoor and outdoor workers, would require employers to provide rest periods and access to drinking water and shade (or climate-controlled environments).

The forthcoming rule is also expected to have provisions for acclimatization, training on heat illness prevention, emergency response, and “heat and high-heat procedures when the temperature equals or exceeds heat thresholds set by the board.”

Other notable state actions

Arizona

The Industrial Commission of Arizona on April 9 unanimously approved a set of recommendations.

The guidance, which isn’t an enforceable standard, is intended for employers. It covers best practices for prevention plans; water, shade and rest breaks; acclimatization; and training.

The state is also working to revise its special emphasis program on heat and will then “evaluate the updated SEP and report on the effectiveness of the improved guidance before the end of the year.”

During the past legislative session, Arizona lawmakers introduced bills that address workplace heat and cold stress prevention.

At press time, the bills remained in the committee stage.

Colorado

In March, the House Health and Human Services Committee approved a bill aimed at starting the process of protecting workers from heat and cold stress.

H.B. 26-1272 would direct the Colorado Department of Labor and Employment to collect data – beginning no later than Jan. 1 – on work-related injuries, illnesses and emergencies caused by heat or cold stress.

It also would require the department to develop by Jan. 1, 2028, a model temperature-related injury and illness prevention plan, or TRIIPP, and make it available on the department’s website.

This is the second attempt by state legislators to pass the bill. H.B. 25-1286 was tabled in March 2025 by the House Business Affairs and Labor Committee.

“We heard that last year’s bill was too prescriptive, and we adjusted accordingly,” Rep. Meg Froelich (D-Greenwood Village), one of the bill’s sponsors, said during a March 18 hearing. “We heard that [extreme temperatures] really [aren’t] a problem, so we’re suggesting that we collect data.

“We ask you to let us begin this journey, to listen to workers, to consider workers when we think about our increasingly hot summers, our crazy cold days that seem to come from nowhere. ‘Prevention’ is one of the P’s in the TRIIPP. If we can plan ahead, we can keep workers healthy. We keep Colorado going.”

At press time, the bill was with the House Appropriations Committee.

Illinois

In March, the House Labor and Commerce Committee approved H.B. 3762, also known as the Workplace Extreme Temperature Safety Act.

However, the bill, which would have covered both heat and cold stress prevention in the workplace, failed to advance out of the House Rules Committee.

New Mexico

The state’s Environment Department published a proposed rule on heat injury and illness prevention for indoor and outdoor workers in March 2025.

In March 2026, the department wrote that it plans to publish a revised regulation and “provide sufficient time for stakeholder comments and engagement.”

At press time, a public hearing on the proposed rule was set for Aug. 3-7.

The state cancelled three previously scheduled hearings that were slated for July 2025, January 2026 and May 2026.

Lawmakers in more than a dozen other states have introduced bills that address workplace heat stress. None of those bills had advanced out of their respective committees as of press time.